https://en.wikipedia.org/wiki/Observable_universe
It refers to the physical limit created by the speed of light itself. No signal can travel faster than light, hence there is a maximum distance, called the particle horizon, beyond which nothing can be detected, as the signals could not have reached the observer yet.
The observable universe has a diameter of approximately 8.8 x 10^26 meters. This is equivalent to 93 billion light-years.
To put that into perspective:
- A light-year is about 9.461 x 10^15 meters.
- The observable universe's diameter is roughly 93 billion light-years.
- Therefore, the diameter in meters is approximately 93 * 10^9 * 9.461 * 10^15 = 8.8 * 10^26 meters.
